A wide variety of organs, including kidneys, lungs, livers, hearts, pancreases, and small intestines are routinely and successfully transplanted. These organs are obtained either from living donors or from cadaveric sources.
In 1998, a total of 12,166 kidney transplants were performed in the United States by programs tracked by the UNOS Transplant Patient DataSource. A total of 45,189 people were on the waiting lists for kidneys as of Sep. 30, 1999. Over 20,000 kidneys were transplanted between Jul. 1, 1995 and Jun. 30, 1997. The graft survival rate for these transplanted kidneys was 93.4% after three months.
The ability to store organs for two or three days prior to transplantation allows sufficient time for histo-compatibility testing of donor and recipient, transport of the organ between transplant centers, preoperative preparation of the recipient, preliminary donor culture testing, and vascular repair of the organ if needed. The efficacy of organ transplantation depends in part on how well the organ is preserved prior to transplantation. Two methods are used to preserve organs prior to transplant: hypothermic storage and continuous pulsatile perfusion. Hypothermic storage by simple cold storage methods involves removal of an organ from a donor followed by rapid cooling. Cooling is achieved by a combination of external cooling and a short period of perfusion with a chilled medium to reduce the core temperature of the organ as quickly as possible. The organs are then immersed in a flush-out medium at from 0° C. to 4° C. Continuous pulsatile perfusion involves the continuous infusion of organs with a preservation solution designed to prevent low temperature injury.
A number of media have been developed for infusing and preserving organs prior to transplantation. Examples of such media include VIASPAN (also known as University of Wisconsin solution; Barr Laboratories, Pomona, N.Y.), University of Wisconsin Machine Perfusion Solution, Hypertonic Citrate Solution, histindine-tryptophan-glutarate solution (HTK Solution), HTK Solution of Bretschneider, Phosphate Buffered Sucrose, EuroCollins Solution, and Collins C2 Solution. However, none of these media are able to extend the preservation of organs past about 72 hours using cold storage methods. Additional preservation time would be useful for tests and for transportation of the organs. Furthermore, media that increase preservation time also can be expected to provide healthier organs for transplants performed within 72 hours.
Accordingly, what is needed in the art are improved media for preserving and storing organs prior to transplant. Such media should be able to extend the preservation period past 72 hours and provide organs with increased functionality upon transplant.